In the operation of rotary equipment operating in an inclined position and handling materials which contain or generate particles of an abrasive nature, problems have been ever present because such particles have been able to reach the sealing area and bring about excessive wear and premature seal failure. Such equipment may include pulverizers, sifters, crushers and furnaces. Previous efforts to overcome early sealing failures in such equipment have included the use of multiple seals arranged in series so that as the innermost seal fails, the next outer seal takes over the primary sealing function. Other previous designs have utilized various liquid flushing arrangements intended to carry particulate material away from the sealing area. While these prior arrangements have provided some improvement in service life, they have often occupied excessive space or been of complex and expensive design. Also, the improvements in service life have often been minimal.